Methods for controlling valves of an internal combustion engine, devices for controlling the valves, and engines employing the methods

ABSTRACT

Methods for improving the efficiency of internal combustion engines are disclosed. In one embodiment, a method of improving the efficiency of an internal combustion engine comprises controlling the motion of an exhaust valve associated with a cylinder of the internal combustion engine. Camshafts and internal combustion engines configured for performing methods of the instant invention are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of prior, co-pending U.S. applicationSer. No. 11/974,236, filed Oct. 12, 2007, which itself claims thebenefit under 35 U.S.C. 119(e) of U.S. Provisional Application Ser. No.60/829,256, filed Oct. 12, 2006, each of the contents of which areincorporated by this reference in their entirety.

TECHNICAL FIELD

The present invention relates generally to engines and, moreparticularly, to methods for adjusting the movement of valves andincreasing the efficiency in an internal combustion engine. Theinvention further relates to engines employing the methods disclosedherein.

BACKGROUND

The depletion of fossil fuels and increases in greenhouse gases has ledto a worldwide demand for engines that power vehicles more efficiently.Further, increases in gasoline and diesel prices have consumersdemanding that the engines that run the vehicles be more efficient.

In response to these demands from consumers, the automotive industry andthe energy industry are attempting to develop vehicles and fuels thatare more efficient and inexpensive. For instance, the automobileindustry has developed so called “hybrid” engines for use in passengercars, wherein the vehicles employing these “hybrid” engines get bettergas mileage, thus, reducing the operating costs for these vehicles. Theenergy industry has also developed fuels for vehicles that are made fromrenewable energy sources. For instance, ethanol blended gasolines andbiodiesel are becoming more available and cost competitive as comparedto fuels that originate from fossil fuels.

Although these improvements have provided some relief and hope forconsumers of gasoline and diesel fuels, there exists a need for enginesthat burn these fuels more efficiently as well as engines that lastlonger.

SUMMARY OF THE INVENTION

In each of its various embodiments, the present invention fulfills theseneeds by disclosing a method of moving at least one valve of an internalcombustion engine that results in an engine having improved fuelefficiency and a longer life. An internal combustion engine configuredfor performing the methods of the instant invention is furtherdescribed.

In one embodiment, a method of combusting fuel in an internal combustionengine comprises introducing air into a cylinder of an internalcombustion engine, releasing a portion of the air from the cylinder withan exhaust valve associated with a camshaft and compressing theremaining air in the cylinder. The method further includes injectingfuel into the cylinder, igniting the remaining portion of the compressedair and the fuel in the cylinder and exhausting the ignited fuel-airmixture from the cylinder with the exhaust valve associated with thecamshaft.

In yet another embodiment, a method of moving a valve in an internalcombustion engine includes opening an intake valve associated with acylinder during a first stroke of a piston associated with the cylinderand opening an exhaust valve of the cylinder during a second stroke ofthe piston with a camshaft having two lobes in operable communicationwith the exhaust valve. The method also includes performing a thirdstroke or power stroke of the piston and opening the exhaust valve ofthe cylinder during a fourth stroke of the piston with the camshaft.

In yet a further embodiment, a method of timing valves in an internalcombustion engine comprises associating an intake valve and an exhaustvalve with a cylinder of an internal combustion engine and configuring acamshaft with at least two lobes that move the exhaust valve to lift oropen the exhaust valve at least two times during a cycle of the internalcombustion engine.

In other embodiments, internal combustion engines configured forperforming the methods of the instant invention are described. Theinternal combustion engines may be configured to burn fuels including,but not limited to, gasoline, diesel, biodiesel, an alcohol, propane orany combination thereof.

In yet an additional embodiment, a camshaft configured for controlling avalve in an internal combustion engine that performs the methods of thepresent invention is disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of acts involved in an intake strokeof a piston of an internal combustion engine of the present invention.

FIGS. 2A and 2B depict an embodiment of two acts involved in acompression stroke of a piston in an internal combustion engine of theinstant invention.

FIG. 3 shows one embodiment of acts involved in a power stroke of apiston in an internal combustion engine of the instant invention.

FIG. 4 illustrates an embodiment of acts involved in an exhaust strokeof a piston in an internal combustion engine of the present invention.

BEST MODE OF THE INVENTION

The present invention is directed towards methods of controlling themovement of air in an internal combustion engine. By opening an exhaustvalve of the internal combustion engine more than once during tworevolutions of the internal combustion engine, a valve and a seat and,thus, the internal combustion engine operate at a lower temperature thanconventional internal combustion engines. Further, by releasing aportion of air from the cylinder before the compressed fuel-air mixtureis burned, the internal combustion uses less fuel than conventionalengines.

A method of combusting fuel in an internal combustion engine includesintroducing air into a cylinder of an internal combustion engine,releasing a portion of the air from the cylinder, compressing aremaining portion of the air in the cylinder, introducing fuel into thecylinder, igniting the remaining portion of the compressed air and thefuel in the cylinder, and exhausting the ignited fuel-air mixture fromthe cylinder. In the method, the remaining portion of the air in thecylinder may be less than an amount of air introduced into the cylinder.The method may further include opening or lifting an exhaust valve ofthe internal combustion engine at least two times during a cycle of theinternal combustion engine.

Another method of the present invention includes opening an intake valveassociated with a cylinder during a first stroke of a piston associatedwith the cylinder, opening an exhaust valve of the cylinder during asecond stroke of the piston, performing a third stroke of the piston,and opening the exhaust valve of the cylinder during a fourth stroke ofthe piston. In the method, the opening of the exhaust valve may beeffectuated by moving a camshaft associated with the internal combustionengine.

A further method of the present invention includes associating an intakevalve and an exhaust valve with a cylinder of an internal combustionengine and configuring a camshaft that moves the exhaust valve to open,lift, or open and lift the exhaust valve at least two times during acycle of the internal combustion engine.

An internal combustion engine is configured to perform any of themethods of the present invention. The internal combustion engine may beconfigured to run on at least one of diesel, biodiesel, gasoline, analcohol, an alcohol blended fuel, propane or any combinations thereof.In a further embodiment, the internal combustion engine may beconfigured with a carburetor or a fuel injection system. In anotherembodiment, the internal combustion engine runs at a cooler temperaturethan a conventional engine. In yet a further embodiment, an exhaustvalve and a seat of the internal combustion engine are at a coolertemperature during operation of the internal combustion engine ascompared to a conventional engine.

A camshaft configured to move the valves of an internal combustionengine capable of performing any of the methods of the present inventionis also disclosed.

A vehicle comprising an internal combustion engine of the presentinvention is also disclosed. The vehicle may be an automobile, asemi-tractor, a tractor, a train or a boat.

In another embodiment, the internal combustion engine may be associatedwith a generator for generating electricity.

In the exemplary embodiments, an internal combustion engine that is moreefficient than a conventional engine is described. While the presentinvention is described in terms of certain specific, exemplaryembodiments, the specific details of the exemplary embodiments are notmeant to be limiting. Various combinations or modifications of theexemplary embodiments may be made without departing from the scope ofthe invention.

EXAMPLE 1

Referring now to FIG. 1, there is shown a partial view of one embodimentof an internal combustion engine depicting an intake stroke of theinternal combustion engine. FIG. 1 depicts an intake 1 and an exhaust 2of a cylinder 7. The cylinder 7 is also associated with an intake valve3, an exhaust valve 4, an injector 5, and a piston 6. The piston 6 isoperably connected to a connector rod 8 which drives crankshaft 9. Asillustrated in FIG. 1, the cylinder 7 is filled with air shown witharrows 10 as the piston 6 moves downward in stroke one of the piston 6.It will be apparent by those of ordinary skill in the art that referenceto “downward” or “upward” in describing the present invention isexemplary based on the orientation of the internal combustion engine inthe FIG. 1.

FIGS. 2A and 2B depict an upward motion of the piston 6 after thedownward motion of FIG. 1. In this exemplary embodiment, the piston 6moves in an upward direction and the air 10 is compressed in stroke twoof FIGS. 2A and 2B. During stroke two, the exhaust valve 4 is opened torelease a portion of the volume of air in the cylinder 7, the exhaustvalve 4 is subsequently closed, and the remaining portion of the air 10not released is compressed in the cylinder 7 during stroke two. Thus,the exhaust valve 4 is opened to release some of the air 10 and closedsuch that the remaining air 10 may be compressed during stroke two ofthe piston 6. The exhaust valve 4 may be opened and closed during stroketwo in any manner known by those of ordinary skill in the art. In oneembodiment, the exhaust valve 4 is opened and closed by configuring acamshaft of the internal combustion engine in an appropriate fashion.For instance, the camshaft that controls the opening and closing of theexhaust valve 4 may be ground or configured to have two lobes that openthe exhaust valve 4 twice during two revolutions of the crankshaft.

By opening the exhaust valve 4 during stroke two, less than 100% of theair 10 introduced into the cylinder 7 is compressed during stroke two.By removing a portion of the air 10 from the cylinder 7 and usingapproximately the same compression pressure as an engine having 100% ofthe air compressed, it is expected that less fuel will be used. Thecompression may be maintained at about the same compression pressure bydecreasing a volume of the cylinder. In various embodiments, the volumeof the cylinder may be decreased by modifying (i.e., shaving) the headsassociated with the cylinder or by using high dome pistons. In oneembodiment, a 72 cubic centimeter (cc) cylinder may be reduced to abouta 36 cc cylinder, and about 50% of the air may be removed from thecylinder 7 by opening the exhaust valve 4 during stroke two, thusmaintaining approximately the same compression in the 36 cc cylinder asthe 72 cc (cubic centimeter) cylinder, but using less air and, thus,less fuel.

The release of the portion of the air 10 before ignition in the cylinder7 also enables the exhaust valve 4 and associated seat to be cooledduring operation of the internal combustion engine, thus enabling theinternal combustion engine of the present invention to run at a coolertemperature as compared to an internal combustion engine that is notconfigured to open or move the exhaust valve twice during tworevolutions of the crankshaft. The amount of air 10 that will becompressed in stroke two may be determined with routine experimentationby those of ordinary skill in the art and may be optimized depending onthe number of cylinders, the number of valves, the size of thecylinders, the type of fuel, or combinations thereof used in theinternal combustion engine.

Referring now to FIG. 3, stroke three or the power stroke of the piston6 is depicted. In the power stroke, fuel 11 is introduced into thecylinder 7 through the injector 5 and into the compressed air. Sinceless than 100% of the air that is introduced into the cylinder 7 iscompressed in the cylinders of the present invention as compared to aconventional engine, the engine may also be configured to introduce lessfuel into the cylinder. In one embodiment where 50% of the airintroduced into the cylinder is removed, the amount of fuel introducedinto the cylinder may also be reduced to about 50% of the fuel thatwould be introduced into a cylinder of a conventional engine.

It will be appreciated by those of ordinary skill in the art that theamount of fuel introduced into the cylinder may vary and will bedetermined, at least in part, by an amount of air that is removed fromthe cylinder and/or compressed in the cylinder. Ignition of thefuel-compressed air mixture during the power stroke causes the piston 6to move downward and impart power to the internal combustion engine. Bycompressing less than 100% of the air 10 introduced in the cylinder andintroducing a smaller amount of fuel in the cylinder, the internalcombustion engine and, thus, the power stroke use less fuel in theinternal combustion engine of the present invention than the powerstroke in a conventional internal combustion engine that compresses 100%of the air introduced in the cylinder, Further, the fuel of the internalcombustion of the instant invention is used more efficiently as comparedto that of a conventional internal combustion engine because a fullstroke of the piston 6 is being expanded, while using less fuel than aconventional engine.

FIG. 4 depicts an exhaust stroke (stroke 4) of the piston 6 of thecylinder 7 after the power stroke, thus removing the ignited fuelcompressed air mixture.

EXAMPLE 2

In another embodiment, a camshaft is designed for a Cummins brand 5.9Liter Diesel engine having six cylinders and 12 valves offered in a 1997Dodge brand pickup as follows. An exhaust camshaft of the Cummins brand5.9 Liter Diesel engine is designed with the specifications of the stockcamshaft and the addition of a second lobe placed on the exhaustcamshaft in order to open the exhaust valve during a second orcompression stroke of the piston. The exhaust camshaft is designed tohave the second lobe ground on the exhaust camshaft according to thefollowing specification: in a range of from about 20° to about 30° BBDC(before bottom dead center) and in a range from about 91° to about 101°ABDC (after bottom dead center). In one illustrative embodiment, theexhaust camshaft is designed to have the second lobe ground to about 25°BBDC and about 96° ABDC.

The exhaust camshaft of this example is placed into a Cummins brand 5.9Liter Diesel engine and the engine is configured for operation. In otherembodiments, the engine may be configured with a turbo charger, asupercharger, or without the turbo charger or supercharger.

The exemplary embodiments described herein are not intended to limit theinvention or the scope of the appended claims. Various combinations andmodifications of the examples or embodiments described herein may bemade without departing from the scope of the present invention and allmodifications and combinations are meant to be included within the scopeof the present invention.

1. A method of combusting fuel in an internal combustion engine, themethod comprising: introducing air into a cylinder of an internalcombustion engine; releasing a portion of the air from the cylinderduring a compression stroke of the internal combustion engine;compressing a remaining portion of the air in the cylinder with a pistonsuch that a compression pressure of the remaining portion of thecompressed air is approximately the same as a compression pressure of anentire amount of the air introduced into the cylinder and compressedwithout releasing the portion of the air from the cylinder; introducingfuel into the cylinder; igniting the remaining portion of the compressedair and the fuel in the cylinder; and exhausting the ignited fuel-airmixture from the cylinder.
 2. The method according to claim 1, whereinthe remaining portion of the air in the cylinder is less than the entireamount of air introduced into the cylinder.
 3. The method according toclaim 1, further comprising opening or lifting an exhaust valve of theinternal combustion engine at least two times during a cycle of theinternal combustion engine.
 4. The method according to claim 1, furthercomprising opening or lifting an intake valve of the internal combustionengine at least two times during a cycle of the internal combustionengine.
 5. A method of moving a valve in an internal combustion engine,the method comprising: opening an intake valve associated with acylinder during a first stroke of a high dome piston associated with thecylinder; opening an exhaust valve or an intake valve associated withthe cylinder during a second stroke of the high dome piston with acamshaft in operable communication with the exhaust valve or the intakevalve; performing a third stroke of the high dome piston; and openingthe exhaust valve associated with the cylinder during a fourth stroke ofthe high dome piston with the camshaft.
 6. The method according to claim5, wherein the opening of the exhaust valve or the intake valve iseffectuated by movement of the camshaft having two lobes configured foropening the exhaust valve or the intake valve associated with theinternal combustion engine.
 7. A method of configuring an internalcombustion engine, the method comprising: associating an intake valveand an exhaust valve with a cylinder of an internal combustion engine;configuring a camshaft to release a portion of air introduced into thecylinder from the cylinder during a compression stroke and a remainingportion of air in the cylinder is compressed during the compressionstroke; associating a piston and a head with the cylinder of theinternal combustion engine; and configuring the piston, the head or acombination thereof such that during the compression stroke, a pressureof the remaining portion of the compressed air is substantially the sameas a pressure of an entire amount of air introduced into the cylinderand compressed during the compression stroke.
 8. An internal combustionengine configured to perform the method of claim
 1. 9. The internalcombustion engine of claim 8, wherein the internal combustion engine isconfigured to run on diesel, biodiesel, or a combination thereof. 10.The internal combustion engine of claim 8, wherein the internalcombustion engine is configured to run on gasoline, an alcohol, propaneor a combination thereof.
 11. The internal combustion engine of claim10, wherein the internal combustion engine is configured with a fuelinjection system or a carburetor.
 12. The internal combustion engine ofclaim 8, wherein the internal combustion engine runs at a coolertemperature than an engine not configured to release the portion of theair from the cylinder during the compression stroke.
 13. An internalcombustion engine configured to perform the method of claim
 5. 14. Aninternal combustion engine configured to perform the method of claim 7.15. The method according to claim 1, wherein the portion of the air isreleased from the cylinder with an exhaust valve associated with thecamshaft.
 16. The method according to claim 1, wherein the air releasedfrom the cylinder during the compression stroke is not ignited.
 17. Themethod according to claim 7, wherein the piston comprises a high domepiston.
 18. The method according to claim 7, wherein configuring thehead comprises shaving the head associated with the cylinder.
 19. Themethod according to claim 1, wherein the piston is a high dome piston.